Take the 2-minute tour ×
Unix & Linux Stack Exchange is a question and answer site for users of Linux, FreeBSD and other Un*x-like operating systems.. It's 100% free, no registration required.

On a Debian system, one can type pager in order to use whatever pager program happens to be default/available. By default, less is used, and if not available, the lesser more gets to do the job. Is such a thing available in other Unix and Linux systems?

share|improve this question

3 Answers 3

up vote 4 down vote accepted

The unix tradition is for applications that want to call a pager to call $PAGER, i.e. use the contents of the environment variable PAGER as a command name. (Whether shell metacharacters are expanded in $PAGER is not consistent between applications.) The unix tradition further uses more if the PAGER variable is not set. There is a similar tradition for text editors: use $EDITOR (or, for historical reasons, $VISUAL), falling back to vi.

Having a command named pager is specific to Debian (and derivatives, including Ubuntu). /usr/bin/pager is in fact a symbolic link to /etc/alternatives/pager, which points to the the “best” available pager (the Debian maintainers decide which is best, and the system administrator can override their choice), using the alternatives framework.

Debian also provides /usr/bin/sensible-pager. This script runs $PAGER if the variable is set, and falls back to pager otherwise. Its purpose is to be used in programs where a single pager path has to be hard-coded. This behavior is documented in the Debian policy manual.

share|improve this answer
    
Just as an addendum, while not included by default, a pager generic could be used by the alternative system that is found in Red Hat derivatives such as Fedora. Also, if one really wanted to, I'll bet one could implement such a system on other Unixes since I've seen alternative frameworks implemented in perl. –  Steven D Jan 4 '11 at 20:42
    
@Steven: It's not surprising that Red Hat's alternatives look like Debian's. And the framework is implemented as a Perl script (/usr/bin/update-alternatives) — or was. –  Gilles Jan 4 '11 at 21:13

All Linux-Distributions I have used so far (Gentoo, Debian, Slackware, Fedora, OpenSuse) had an Environment-Variable called PAGER which set the pager (default, as said, less). It's set in your shell environment.
I think the command man uses this variable..

share|improve this answer
$ update-alternatives --list pager
/bin/less
/bin/more
/usr/bin/pg
/usr/bin/w3m

YMMV depending on what you have installed, but this is Debian-specific (well, and derivatives too).

Customarily one uses $PAGER with a fallback to more.

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.